Internal combustion engines employ the Otto spark ignition cycle and the Carnot compression ignition cycle, in the engines of the type under consideration. These distinct engine cycles are carried out in various forms of engines which are recognized conventionally as either two cycle or four cycle, including reciprocating as well as rotary engines. This invention is particularly concerned with the prior art spark ignition Otto cycle engine which employs compression to heat a combustible admixture of gas and air, with ignition thereof by a timed spark heretofore produced by a high tension electrical system and with commutation to the multiplicity of spark plugs involved; and employing step-up coils, condensers and breaker points, all combined in a complex system using both low and extremely high voltage electricity. Thus, the prior art has resorted to complex and expensive means so as to cause timed ignition and burning of gases and/or atomized fuels, in this type of widely accepted heat engines. Therefore, it is a general object of this invention to entirely eliminate the complications of high tension spark ignition in Otto cycle engines, and to replace the same with a greatly simplified and much more practical Timing Chamber Ignition.
The ignition system herein disclosed is universally applicable to internal combustion Otto cycle engines of all types. That is, this ignition system is operable in carbureted or atomized fuel injected Otto cycle engines, regardless of the type of fuel employed, providing a stoichiometric ratio of fuel to air exists to support combustion. Therefore, it is a primary object of this invention to provide a method and apparatus for timed ignition of internal combustion engines by providing pressure responsive means to ignite the fuel-air mixture with inherently correct results, and eliminating the conventional high tension spark. ignition with its advance and retard system of breaker points. The method of ignition herein disclosed can be practiced in any reciprocating or rotary type engine presently used, simply by replacing the spark plugs and by removing the present high tension commutated spark generating system. The method herein disclosed involves response to the compression of the fuel-air mixture in the engine combustion chamber, which normally occurs before top dead center of the engine crank motion, by transferring a pressure front from said compression mixture and into a closed chamber that is in open communication with the combustion chamber, and by positioning an igniter means in the closed chamber for contact with the said compression mixture for its ignition.
With this invention, there is progressive movement of the pressure front into the closed chamber, preferably an elongated ignition chamber that is penetrated by the pressure front to the position of the igniter means. At this pressure front level and/or position within the closed chamber, ignition occurs and continues in the usual manner. The results herein disclosed differ from prior art glow plug technology in that the normal use of a glow plug does not provide any timing whatsoever. The advancement of the ignition time in this invention is automatically controlled by the density of the charge During idle the throttle is nearly closed and a very high vacuum exists in the intake system of the engine, and thus the density in the combustion chamber is correspondingly low, so that the fuel-air mixture reaches the igniter means later in time. However, during open throttle conditions the charge is at greater density and the fuel-air mixture reaches the igniter means sooner in time. It is to be understood that the time at which the igniter means is reached by the pressure front relates to the dynamic position of the crank shaft, or equivalent, with respect to its top dead center position and transition into the power cycle or stroke of the engine.
It is another object of this invention to advantageously employ a gas spring effect which is inherent with gasses captured in an air space. Heretofore, glow plugs and the like have simply been exposed to gasses within the combustion chamber of the engine, devoid of timing control of any kind. However, with the present invention the elasticity of the gasses in an ignition chamber functions as a spring which controls the penetration of the pressure front of compressed mixture from the combustion chamber and into the ignition chamber. In practice, the ignition chamber is of a configuration whereby igniter means is positioned therein with respect to the response of the air spring to said pressure front and so that movement of the pressure front into contact with the igniter means occurs when ignition is required. As will be described, the ignition chamber is comprised of a timing zone open to the combustion chamber, and a buffer zone fixed or adjusted as to displacement in order to provide the required gas spring effect. When ignition occurs, all combustible gases within the timing zone as well as within the buffer zone are burned, and continuing into the combustible mixture compressed within the combustion chamber.
It is still another object of this invention to advantageously employ a gas shied effect which is inherent with the presence of previously burnt gases in the ignition chamber as they are controlled by the aforesaid gas spring effect. With the present invention, reduced combustion chamber pressure during the engine intake cycle or stroke causes extension of the said gas spring and thereby occludes the igniter means with non combustible gasses. The occlusion precludes ignition of the cumbustible gas-air intake mixture. However, when compression occurs in the combustion chamber, the pressure front therefrom enters through the passageway and into the timing zone of the ignition chamber where it continues to move toward the igniter means as compression increases. Accordingly, the pressure front establishes a boundary layer between burnt gasses in the captured air space of the buffer zone and the combustible gasses progressively penetrating the timing zone to subsequently contact the igniter means positioned therein at the point of ignition. The point of ignition is thereby precisely operatIve according to the air spring's predetermined response to the pressure conditions within the combustion chamber of the engine.